This application is based upon and claims the benefit of priority from Japanese patent application No. 2007-186895, filed on Jul. 18, 2007, the disclosure of which is incorporated herein in its entirety by reference.
1. Field of the Invention
The present invention relates to a semiconductor apparatus in which a wired board is mounted on a semiconductor chip, and a method of manufacturing the semiconductor apparatus.
2. Description of the Related Art
For example, as disclosed in Japanese Patent Laid-Open No. 9-260536, in the semiconductor apparatus according to the present invention, a flexible wired board is allocated on a main surface of the semiconductor chip through the elastomer. The semiconductor apparatus is configured so that an electrode pad of the semiconductor chip and a lead part of a wiring allocated in an aperture part of the wired board are electrically connected, an external terminal is included on the other surface of the wired board, and the electrode pad of the semiconductor chip allocated in the aperture part of the wired board, and the lead part are covered with sealing material made of insulating resin.
Since such a semiconductor apparatus according to the present invention is configured so that the electrode pad of the semiconductor chip and the lead part of the wired board are connected at the aperture part provided on the wired board, the semiconductor apparatus is structured so that the external terminal can not be provided just below the electrode pad of the semiconductor chip.
Year by year, since an operation rate of the semiconductor apparatus has been increased, if a distance from the electrode pad of the semiconductor chip, e.g. a wiring length, becomes long, the operation rate may be lowered. Thus, there is a requirement to largely shorten the wiring length of the semiconductor apparatus to obtain favorable electrical characteristics.
Since the external terminal can not be provided just below the electrode pad of the semiconductor chip, the number of the external terminals may have to be reduced, which are allocated in an area, in which the semiconductor chip is mounted, of the wired board. The number of the external terminals of the semiconductor apparatus has been increased, and it becomes necessary to allocate the external terminals outside the area, in which the semiconductor chip is mounted, of the wired board, so that an area of the wired board may be increased. If the area of the wired board is increased, a package size of the semiconductor apparatus is increased. Further, if the area of the wired boards is increased, the number of the wired boards to be produced for each shot is reduced when the wired board is produced, and a cost of the wired board is increased.
The semiconductor apparatus according to the present invention is configured so that the semiconductor chip is mounted on the wired board through the elastomer (elastic material) to improve the reliability of the secondary installation of the semiconductor apparatus. However, while it is possible to reduce the stress because of the difference between the thermal expansion coefficients, and to improve the reliability of the secondary installation by mounting the semiconductor chip on the wired board through the elastomer, the elastomer is expensive material, so that the production cost of the semiconductor apparatus may be increased.
In addition, in the semiconductor apparatus according to the present invention, the semiconductor chip is mounted on a flexible wired board according to the TAB (Tape Automated Bonding) method, so that the necessary mounting accuracy may have not been obtained because of the influence of the sheet size tolerance or the roll, or the expensive mounting facility may have be necessary. In addition, since the pitch of the electrode pad and the wiring of the semiconductor apparatus has been narrowed, it becomes necessary to improve the mounting accuracy.